Biomedical subjects

Jiann-Ming Wu

Publications and source records attributed to Jiann-Ming Wu.

13 recordsLinked to original sources

PubMed2006

Impact of previous abdominal surgery on laparoscopic appendectomy for acute appendicitis.

BACKGROUND: Laparoscopic appendectomy is one of the most commonly performed laparoscopic procedures. Impact of previous abdominal surgery on laparoscopic appendectomy has not been previously reported. METHODS: From January 2001 to December 2005, 2029 patients with clinically suspected acute appendicitis underwent laparoscopic surgery in our hospital. Of these, 234 patients (11.5%) were found to have other pathology by intraoperative or histologic findings and were excluded from the study. The 1795 patients who underwent laparoscopic appendectomy for acute appendicitis were divided into three groups: group 1, patients without a history of previous abdominal surgery (n = 1652, 92%); group 2, patients with a history of upper abdominal surgery (n = 20, 1.1%); group 3, patients with a history of lower abdominal surgery (n = 123, 6.8%). Data were collected retrospectively by chart review and analyzed for conversion rate, operative time, intraoperative and postoperative complications, and hospital stay. RESULTS: Of the 1795 patients, 13 (0.7%) were converted to open appendectomy because of technical difficulty. Overall mean operative time was 57.2 (range, 20-225) min. There was no mortality or intraoperative complications. Overall postoperative complication rate was 10.7% (n = 193): rate of surgical wound infection was 8.2% (n = 147), surgical wound seroma 1.3% (n = 24), and intra-abdominal abscess 0.8% (n = 14). Overall postoperative hospital stay averaged 3.2 (range, 0-39) days. There were no significant differences between the three groups regarding the conversion rate (0.8% vs. 0% vs. 0%, p = 0.567), operative time (57.3 vs. 55.8 vs. 56.9 min, p = 0.962), postoperative complication rates (10.7 vs. 10 vs. 12.2%, p = 0.863), and hospital stay (3.2 vs. 3.6 vs. 3.1 days, p = 0.673). CONCLUSIONS: Previous abdominal surgery, whether upper or lower abdominal, has no significant impact on laparoscopic appendectomy for acute appendicitis.

Acute Disease↗

PubMed2006

Laparoscopic versus open appendectomy for perforated appendicitis.

The role of laparoscopic appendectomy (LA) for perforated appendicitis is under investigation. A retrospective study was conducted to compare the outcomes of laparoscopic versus open appendectomy (OA) for perforated appendicitis. From January 2001 through December 2003, 229 patients with perforated appendicitis were treated at Far-Eastern Memorial Hospital. LA was successfully completed in 91 of 99 patients. OA was performed in 130 patients. Operation time was longer in the LA group (mean +/- SD = 96.1 +/- 43.1 vs. 67.8 +/- 32.2 minutes, P < 0.01). Return of oral intake was faster in the LA group (3.2 +/- 2.4 vs. 5.0 +/- 7.0 days, P < 0.01). The intravenous antibiotic usage period was shorter in the LA group (4.4 +/- 2.8 vs. 6.3 +/- 7.1 days, P < 0.01). The postoperative wound infection rates were 15.2 % (LA group) and 30.7% (OA group). The overall infectious complication rates were 19% in the LA group and 37% in the OA group (P < 0.01). Hospital stay days were shorter for the LA group (6.3 +/- 2.9 vs. 9.3 +/- 8.6 days, P < 0.01). Our results indicated that laparoscopic appendectomy is a safe and effective procedure for treating patients with perforated appendicitis.

Adult↗

PubMed2006

Laparoscopic diagnosis and treatment of small bowel obstruction caused by postoperative intussusception.

Small bowel obstruction is a common problem, especially for patients who have had previous abdominal surgery possibly complicated by postoperative adhesions. In contrast to adhesions, postoperative intussusception is an unusual cause of small bowel obstruction. We report a case of small bowel obstruction that occurred one month after antrectomy for duodenal ulcer with massive bleeding. Laparoscopic surgery was attempted after conservative treatment failed. A segment of jejunojejunal intussusception about 50 cm below the ligament of Treitz was identified and laparoscopic reduction of the intussusception was performed. The patient had an uneventful postoperative course and remained asymptomatic at 10-month follow-up. Although not frequently encountered, postoperative intussusception should be considered a possible etiology in patients with postoperative small bowel obstruction. In experienced hands, the laparoscopic approach offers a feasible option for correct diagnosis and appropriate treatment in this situation.

Adult↗

PubMed2006

Function approximation using generalized adalines.

This paper proposes neural organization of generalized adalines (gadalines) for data driven function approximation. By generalizing the threshold function of adalines, we achieve the K-state transfer function of gadalines which responds a unitary vector of K binary values to the projection of a predictor on a receptive field. A generative component that uses the K-state activation of a gadaline to trigger K posterior independent normal variables is employed to emulate stochastic predictor-oriented target generation. The fitness of a generative component to a set of paired data mathematically translates to a mixed integer and linear programming. Since consisting of continuous and discrete variables, the mathematical framework is resolved by a hybrid of the mean field annealing and gradient descent methods. Following the leave-one-out learning strategy, the obtained learning method is extended for optimizing multiple generative components. The learning result leads to parameters of a deterministic gadaline network for function approximation. Numerical simulations further test the proposed learning method with paired data oriented from a variety of target functions. The result shows that the proposed learning method outperforms the MLP and RBF learning methods for data driven function approximation.

Algorithms↗

PubMed2005

Effects of irradiated tumor vaccine and infusion of granulocyte-macrophage colony-stimulating factor and interleukin-12 on established gliomas in rats.

PURPOSE: We investigated granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-12 (IL-12) infused into the injection site of irradiated tumor vaccine (TV) as therapy for gliomas. METHODS: Rats with subcutaneous RT-2 gliomas were treated with irradiated TV and/or subcutaneous infusion of GM-CSF and/or IL-12 via osmotic minipump 5 days after tumor-cell inoculation. Cytotoxic T lymphocyte (CTL) and natural killer (NK) cell activity were analyzed to investigate immune responses. Rats with intracerebral gliomas were treated with irradiated TV and infused GM-CSF/IL-12 3 days after tumor-cell inoculation. Tumor growth rates and animal survival were followed. Survivors were re-challenged with wild-type RT-2 cells subcutaneously or intracerebrally to study long-term anti-tumor immunity. RESULTS: Rats with subcutaneous gliomas treated with GM-CSF and IL-12 or TV plus GM-CSF or IL-12 did not have increased survival rate (P>0.2), but did have prolonged survival time (P<0.05); in contrast, rats treated with TV plus GM-CSF/IL-12 had increased survival rate (P<0.05) and prolonged survival time (P<0.05) compared with controls. These treatment strategies showed enhanced CTL and NK cell activities. Rats with intra-cerebral gliomas treated with TV plus GM-CSF/IL-12 did not have increased survival rate (P=0.11), but did have prolonged survival time (P<0.0001). Survivors in each group were re-challenged with wild-type RT-2 cells, and all had long-term survival. CONCLUSIONS: Irradiated TV plus continuous localized infusion of GM-CSF/IL-12 may induce a tumor-specific anti-tumor immune response on established subcutaneous or intra-cerebral gliomas, and such a treatment strategy deserves consideration as adjuvant treatment for glioma.

Animals↗

PubMed2005

Laparoscopic appendectomy in pregnancy.

BACKGROUND: Laparoscopic appendectomy (LA) is a safe, effective, and beneficial procedure for the treatment of acute appendicitis. However, limited data are available regarding the safety and feasibility of LA during pregnancy. METHODS: Between January 2001 and August 2004, 1235 patients with clinically suspected appendicitis underwent laparoscopic surgery at our hospital. Eleven patients (0.9%) were pregnant women (mean age, 25 years; age range, 19-37 years; range of gestational age, 4-30 weeks). Clinical data collected retrospectively included demographic information; preoperative, procedural, and postoperative information; and outcome of the pregnancy. RESULTS: All 11 pregnant women underwent laparoscopic surgery without need of conversion. Ten patients underwent LA and were found to have acute appendicitis on histologic analysis. One patient had torsion of the right fallopian tube and a healthy-looking appendix; she underwent detorsion of the fallopian tube and incidental appendectomy. Mean operative time was 50.5 minutes (range, 20-135 minutes). Length of postoperative hospital stay averaged 4.2 days (range, 1-11 days). One patient had a surgical wound infection, which was managed conservatively. Mean follow-up period was 14 months (range, 2-46 months). Seven pregnant women delivered healthy term infants, 2 had planned abortions, and 1 experienced fetal loss due to uterine infection and premature contractions 1 month after LA. Another patient had normal results at prenatal examination. CONCLUSION: Our data support the accumulating evidence that LA is a safe and feasible procedure for the treatment of acute appendicitis in all trimesters of pregnancy. Close maternal and fetal monitoring is essential during and after the operation.

Adult↗

PubMed2005

Laparoscopic diagnosis and treatment of acute small bowel obstruction resulting from a congenital band.

Acute small bowel obstruction is a common problem, especially for those patients with previous abdominal surgery that can cause postoperative adhesions. Acute, non-postoperative small bowel obstruction is less common and has various etiologies. We report a case of acute small bowel obstruction without previous abdominal surgery. The patient underwent laparoscopic exploration, and a congenital band was found to cause direct compression of the ileum and entrapment of a segment of bowel loop. There was evidence of bowel strangulation. The color and peristalsis of the entrapped bowel loop recovered gradually after division of the band, and segmental bowel resection was avoided. He has remained asymptomatic since the procedure. We suggest early and aggressive surgical intervention for patients with acute, non-postoperative small bowel obstruction to avoid possible complications of bowel strangulation and gangrene. A laparoscopic approach may be a safe, feasible, and favorable option for correct diagnosis and appropriate treatment in this situation.

Acute Disease↗

PubMed2004

Laparoscopic splenectomy for idiopathic thrombocytopenic purpura.

BACKGROUND: Laparoscopic splenectomy (LS) has become the treatment of choice for patients with idiopathic thrombocytopenic purpura (ITP) who do not respond to medical treatment. Long-term follow-up data of LS for ITP are scarce. METHODS: From May 1997 to December 2002, we performed 67 LS for patients with ITP. Data were assessed retrospectively. RESULTS: LS was successfully attempted in all 67 patients. There was no surgical mortality. Three postoperative complications (5%) were encountered. The mean operative time decreased significantly from 176.2 minutes in the first 41 cases to 125.2 minutes in the last 26 cases. The mean postoperative hospital stay was 3.2 days. Accessory spleens were found in 3 patients (5%) during the LS. The mean follow-up interval was 23.3 months. The initial response to LS was 83%, and overall remission of ITP was 74%. The preoperative effect of steroid therapy had no significant influence on postoperative remission rate. More significant indicators of LS effectiveness were either an immediate postoperative platelet count surge or an immediate postoperative platelet count >or=100000/microL. CONCLUSIONS: LS can be performed safely with a satisfactory remission rate for patients with ITP who do not respond to medical treatment. Our results indicated that an immediate postoperative platelet count surge and/or an immediate postoperative platelet count >or=100000/microL were positive predictors of long-term remission after LS for ITP.

Adult↗

PubMed2004

Annealing by two sets of interactive dynamics.

This work derives the mean field approximation to the mean configuration of a stochastic Hopfield neural network under the Boltzmann assumption. The new approximation is realized by two sets of interactive mean field equations, respectively estimating mean activations subject to mean correlations and mean correlations subject to mean activations. The two sets of interactive dynamics are derived based on two dual mathematical frameworks. Each aims to optimize the objective quantified by a combiation of the Kullback-Leibler (KL) divergence and the correlation strength between any two distinct fluctuated variables subject to fixed mean correlations or activations. The new method is applied to the graph bisection problem. By numerical simulations, we show that the new method effectively improves in both performance and relaxation efficiency against the naive mean field equation

Algorithms↗

PubMed2002

Learning generative models of natural images.

This work proposes an unsupervised learning process for analysis of natural images. The derivation is based on a generative model, a stochastic coin-flip process directly operating on many disjoint multivariate Gaussian distributions. Following the maximal likelihood principle and using the Potts encoding, the goodness-of-fit of the generative model to tremendous patches randomly sampled from natural images is quantitatively expressed by an objective function subject to a set of constraints. By further combination of the objective function and the minimal wiring criterion, we achieve a mixed integer and linear programming. A hybrid of the mean field annealing and the gradient descent method is applied to the mathematical framework and produces three sets of interactive dynamics for the learning process. Numerical simulations show that the learning process is effective for extraction of orientation, localization and bandpass features and the generative model can make an ensemble of a sparse code for natural images.

Learning↗

PubMed2002

Natural discriminant analysis using interactive Potts models.

Natural discriminant analysis based on interactive Potts models is developed in this work. A generative model composed of piece-wise multivariate gaussian distributions is used to characterize the input space, exploring the embedded clustering and mixing structures and developing proper internal representations of input parameters. The maximization of a log-likelihood function measuring the fitness of all input parameters to the generative model, and the minimization of a design cost summing up square errors between posterior outputs and desired outputs constitutes a mathematical framework for discriminant analysis. We apply a hybrid of the mean-field annealing and the gradient-descent methods to the optimization of this framework and obtain multiple sets of interactive dynamics, which realize coupled Potts models for discriminant analysis. The new learning process is a whole process of component analysis, clustering analysis, and labeling analysis. Its major improvement compared to the radial basis function and the support vector machine is described by using some artificial examples and a real-world application to breast cancer diagnosis.

Journal Article↗

PubMedDate not supplied

Induction of apoptosis and cell cycle arrest in glioma cells by GL331 (a topoisomerase II inhibitor).

BACKGROUND: GL331 is a topoisomerase II inhibitor and, in this study, the effects of GL331 upon rat C6 glioma cells were investigated. MATERIALS AND METHODS: The glioma cells were treated with GL331, then a cytotoxicity assay was done to evaluate the cytotoxic effects of GL331 and flow-activated cell sorter analysis was performed to analyze the cellular apoptosis and cell cycle distribution of the glioma cells. The expressions of p53, p21 and 14-3-3sigma in glioma cells treated with GL331 were investigated by Western blot analysis. RESULTS: GL331 was demonstrated to exert cytotoxic effects upon and induce apoptosis of the C6 glioma cells in a concentration- and time-dependent manner (p < 0.05). GL331 also caused the glioma cells to accumulate in the G2/M-phase of the cell cycle and increased the expressions of p53, p21 and 14-3-3sigma. CONCLUSION: GL331 exerts cytotoxic effects and induces apoptosis in C6 glioma cells, accompanied by cell accumulation in the G2/M-phase and activation of p53, p21 and 14-3-3sigma.

14-3-3 Proteins↗

PubMedDate not supplied

Resveratrol suppresses angiogenesis in gliomas: evaluation by color Doppler ultrasound.

BACKGROUND: The effects of resveratrol (a natural polyphenol) on angiogenesis in rat gliomas were investigated by color Doppler ultrasound (CDUS). The correlation among the tumor growth rate, macroscopic angiogenesis measured by CDUS and microscopic angiogenesis was assessed by immunohistochemical staining. MATERIALS AND METHODS: Fischer rats were subcutaneously inoculated with rat RT-2 glioma cells and treated with resveratrol for 4 weeks. The tumor size was measured and the animal survival followed. CDUS examination was used to measure tumor blood flow shown as the color Doppler vascularity index (CDVI). Immunohistochemical staining of CD31 was carried out to assess the microvessel density (MVD) of the tumors. The CDVI, MVD and tumor size were correlated. RESULTS: Rats treated with resveratrol (40 mg/kg/day) had slower tumor growth rates than those of the control groups (p < 0.05). The CDVI, MVD and tumor size were significantly correlated (linear regression, p < 0.0001). CONCLUSION: Resveratrol-suppressed glioma growth was significantly correlated with the inhibition of macroscopic and microscopic angiogenesis.

Angiogenesis Inhibitors↗